System Clock Distribution in a Distributed Computing Environment

1. A distributed computing system comprising: a clock generator configured to generate a first clock signal of a first frequency; and a first computing node comprising: at least two integrated circuit die; a plurality of clock input ports configurable to receive a clock input signal, wherein a clock input port is dynamically selected during operation to receive the first clock signal based at least in part on a system clock distribution scheme; an external communications interface configured to: communicate with a second computing node by clocking data into or out of the first computing node using the first clock signal when communicating with the second computing node, wherein the second computing node comprises at least two integrated circuit die; and communicate with an external computing device operating using a second clock signal at a second frequency that is different from the first frequency, wherein, when communicating with the external computing device, the external communications interface is further configured to: determine the second frequency of the second clock signal; generate a substitute clock signal operating at the second frequency; and communicate with the external computing device using the substitute clock signal in place of the first clock signal.

2. The distributed computing system of claim 1 , wherein the external communications interface is further configured to communicate serially or in parallel with the external computing device.

3. The distributed computing system of claim 1 , wherein the first frequency is higher than the second frequency.

4. The distributed computing system of claim 1 , wherein the external communications interface comprises at least one of a first shift register configured to receive data from the external computing device or a second shift register configured to send data to the external computing device using the substitute clock signal.

5. The distributed computing system of claim 4 , wherein the first computing node processes the data from the first shift register or the second shift register using the first clock signal.

6. The distributed computing system of claim 1 , wherein the first computing node is configured to receive a communication from the external computing device, and wherein the external communications interface is further configured to determine the second frequency of the second clock signal based at least in part on the communication.

7. The distributed computing system of claim 1 , wherein the first clock signal corresponds to a master primary clock signal.

8. The distributed computing system of claim 1 , wherein the second clock signal is of the same frequency as a master clock signal of the external computing device.

9. The distributed computing system of claim 1 , wherein the first computing node further comprises an internal function unit that processes data using a clock signal of the first frequency, wherein the data is received at the external communications interface from the external computing device using the substitute clock signal.

10. The distributed computing system of claim 1 , wherein the first computing node comprises a pass-through device that passes data received from the external computing device to the second computing node.

11. The distributed computing system of claim 1 , wherein the system clock distribution scheme comprises a synchronous clock distribution scheme.

12. The distributed computing system of claim 1 , wherein the system clock distribution scheme divides a plurality of computing nodes into a plurality of clusters, wherein at least one cluster of the plurality of clusters includes the first computing node.

13. The distributed computing system of claim 12 , wherein at least one cluster of the plurality of clusters receives a different clock signal than at least one other cluster of the plurality of clusters.

14. A method of device communication, the method comprising: receiving a first clock signal of a distributed computing system at a clock input port of a computing node of the distributed computing system, wherein the clock input port is dynamically selected during operation of the distributed computing system based at least in part on a system clock distribution scheme, and wherein the computing node is one of a plurality of computing nodes of the distributed computing system; detecting, by the computing node of the distributed computing system, a communication from an external computing device, wherein the first clock signal of the distributed computing system is configured to operate at a first frequency when not in communication with the external computing device; determining based at least in part on the communication that a first clock signal of the external computing device operates at a second frequency that differs from the first frequency; generating a second clock signal at the distributed computing system, the second clock signal operating at the second frequency; and communicating with the external computing device using the second clock signal.

15. The method of claim 14 , wherein the first frequency is higher than the second frequency.

16. The method of claim 14 , further comprising continuing to use the first clock signal of the distributed computing system for internal communication while using the second clock signal for communicating with the external computing device.

17. The method of claim 14 , wherein communicating with the external computing system using the second clock signal further comprises receiving data from the external computing device using the second frequency.

18. The method of claim 17 , further comprising processing the received data at the distributed computing system using the first clock signal of the distributed computing system after the data is received from the external computing device.

19. The method of claim 14 , wherein communicating with the external computing system using the second clock signal further comprises transmitting data to the external computing device using the second frequency.

20. The method of claim 14 , wherein the communication from the external computing device includes a signal corresponding to the first clock of the external computing device.

21. The method of claim 14 , wherein the first clock signal of the distributed computing system corresponds to a master primary clock signal.

22. The method of claim 14 , wherein the first clock signal of the external computing device comprises a master clock signal of the external computing device.

23. The method of claim 14 , further comprising queuing data processed at the distributed computing system using the first clock signal, the queued data communicated with the external computing device using the second clock signal.